Method of making flexible-bolt blanks.



E. l. nouns. METHOD OF MAKING FLEXIBLE BOLT BLAN KS.

APPLICATION FILED FEB. 23. I9I5.

1,250,148. Patented Dee. 18,1917.

|| I' I] I II II II I INVENTOR gigs/55555 I I I a. I WAIM UNITED sTATEs PATENT ETHAN'I. DODDS, OF PITTSBURGH, PENNSYLVANIA, A SSIGNOR T0 FLANNERY -BOL'I. COMPANY, OF PITTSBURGH, PENNSYLVANIA.

METHOD OF MAKING FLEXIBLE-BOLT BLAN KS.

To all whom/it may concern: V

.Be it known that I, ETHAN I. Donns, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Making Flexible-Bolt Blanks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in method of making blanks for flexible track and other bolts, the object being .to

simplify the process of manufacturing the blanks whereby the cost of manufacture will transverse section of the headed blank and.

be greatly reduced, and the output materially increased. w

The invention consists in forming a long cylindrical bar with'one or more slots extending throughout the length of the latter, twisting said bar'while hot, cutting the bar into boltblanks and heading'and threading the blank to produce the bolt.

' In the acoompanymg drawings, Figure 1 is a view of the slotted and twisted'bar; Fig. 2 is a bolt blank cut from said bar; Fig. 3 is a view in section of the blank; Fig. 4 is a view of the blank headed; Fig. 5 is a view in Fig. 6 is a view of the threaded bolt.

slotted throughout its length, the slots being closed without welding the walls thereof, and

the slotted bar is then twisted throughout its length so that the slots will be in the form of spirals extending throughout the length of that part of the bar from which the bolt blanks 2 are cut. rolling a flat bar betweenrolls as described in mypending application No.12662 filed January 16th, 1915, or a cylindrical b'ar may be slotted by a suitable tool or be'passed be tween rolls haying one or more cutting or grooving ribs.

' I prefer to havetwo slots located at oppo site sides of the bar, off the center of the" around-the same.

latter, and passing more than half wa through as shown in Figs. 8 and 5, althoug 1 the number of slots employed is not essential.

I also prefer to roll the bar 1 from a slab or bar o metal as disclosed by me in the Specification of Letters Patent.

The bar may be formed. by.

Patented Dec. is, 1917i.

Application filed February 23, 1915. Serial No. 10,013. 1

application above referred to. After it has been rolled or otherwise formed, and while hot, 1t is twisted from end to end, in' any ordmarytwistingmachine. Bars thus treated or formed may be made in any mill and sold direct to bolt manufacturers.

To make bolts from the bar, the latter is reheated and is then fed to a machine which upsets the head and cuts 0d the blank as shown in Fig. 4:.

By twisting the bar, the twist is constant and uniform from end to end, and consequently is uniform in the blanks that are cut from the bar. The upsetting of the heads welds the wall slots at the head but leavcs the walls of the slots in the shank disconnected thus permitting the shank to give or yield, as is well known in this type of bolt.

. After the blanks have been cut from the bar, the threads are then either hot or cold rolled, or they may be cut.

Having fully described my invention what 1 I claim as new and desire to secure by Letters-Patent, is

1. The method herein described of making 2. The method herein described of making I flexible bolt blanks consisting in providing a bar with a slot extending more than half way, but not wholly through the bar, closing the slot without welding'the walls thereof, rounding the bar into cylindrical shape in cross section, and twisting the bar so as to carry the slot spirally around the same.

3. The method herein described of making flexible bolt'blanks consisting in providing a bar with, slots extending throughout 1ts length,-and at opposite sides, each slot ex-' tending more than half way but not wholly through the bar, closing welding the wall thereo rounding the bar into cylindrical shape in cross-section and twisting the bar to carry the slots spirally throu hout its length at a plurality of points,

each ot extending more than half way, but

the slots without Aion in the pmsance of two ,11%

. (Z in, twistmg the ha a amund the same, and cuttmg bolt blanks.

scrib 

